Electric connectors



Aug. 8, 1961 w. GIBBON 2,995,615

ELECTRIC CONNECTORS Filed June 1a, 1956 In ventor willl dm Gibbon Vi/ MWA? Attorney;

United States Patent F 2,995,615 ELECIRIC CONNECTORS William Gibbon,Liverpool, England, assignor to British Insulated 'Callenders CablesLimited, London, England, a British company Filed June 13, 1956, Ser.No. 59 1,0452 Claims priority, application Great Britain Sept. 6, 1955 1Claim. (Cl. 174-90) This invention relates to improvements in electricalconnectors which, although intended primarily for making a connectionbetween an overhead conductor and a tapping therefrom, may be used formaking a connection between other conductors, for example, a mainconductor and a branch conductor in an underground system. The connectorcan be used to make the connection without cutting the main conductor.

According to the present invention an electrical connector comprises twodeformable metal members, one of which is adapted to be fitted withinthe other by a relative axial sliding movement of the two members. Whenthe two members are thus brought into engagement, their engagingsurfaces are such as to prevent any substantial relative movement of thetwo members both radially outwards and also radially inwards. Each ofthe two members is provided with a groove and when the two members arebrought into engagement, the two grooves co-operate to provide a singlelongitudinally extending through passage for the reception of one of theconductors. The inner of the two members is also provided with alongitudinally extending passage for the reception of the otherconductor, the two conductors thus being separated by an interveningportion of the inner member of the connector.

The inner member, preferably, is located wholly within the outer memberin a direction at right angles to the axis of the connector, theconductor housed in the inner member being then located wholly withinthe outer member. Location of the inner member wholly within the outermember is preferable since the inner and outer members can then be soconstructed as to provide for a smooth continuation of the adjacentportions of the exterior surfaces of the outer member over the exteriorsurface of the inner member. This facilitates the application ofcompression jaws of simple construction to the outer member for thepurpose of effecting the deformation of the two members to provide ajoint between the two conductors. The application of insulating materialto the connector after completion of the joint, should such applicationbe required, is also facilitated.

The invention will be described further with the aid of the accompanyingdrawings illustrating examples of construction in accordance with theinvention.

It will be understood that in each case the connector comprises twodeformable metal members adapted to be brought into engagement by arelative axial sliding movement.

FIGURE 1 is an end elevation of one form of connector ready forcompression, the inner and outer members and the two conductors to beconnected being shown assembled.

FIGURES 2 and 3 are side elevations of the outer and inner membersrespectively.

FIGURE 4 is an end elevation of a somewhat modified form of outer memberas compared with that shown in FIGURES 1 and 2.

FIGURE 5 is a side elevation of the outer member shown in FIGURE 4.

FIGURE 6 is an end sectional elevation illustrating the effect ofcircular compression applied to an electrical connector having an outermember constructed in the manner shown in FIGURE 7.

latented Aug. 8, 1961 FIGURE 7 is a sectional end elevation of aconnector which has been compressed into a non-circular crosssection.

FIGURE 8 of the drawing is a longitudinal view of the device taken alongline VIIIVIH of FIGURE 7.

Reference will be made first of all to FIGURES l-3 from which it will beseen that the connector has an outer member 1 and an inner member 2.These are both made of metal, and are brought into engagement by arelative axial sliding movement. The outer member 1 has three walls, twoof these being designated by the reference numerals 3 and the otherwall, by the reference numeral 4. For convenience of description thewalls 3 will be referred to as the side walls of the outer member andthe wall 4 as the lower wall of the outer member 1. The two side walls 3are spaced apart by an appropriate distance and merge into the lowerwall 4. The two side walls and the lower wall thus eooperate to formbetween them a channel-shaped member having a channel 5, shown in FIGURE4, which extends from one end of the outer member 1 to the other end.The channel is symmetrical on opposite sides of the mid-longitudinalplane Iof the outer member 1 and is bounded at its upper part by a pairof flat parallel sur-' faces 6 (see FIGURE 4) and at its central part bya pair of flat parallel surfaces 8, the latter being spaced apartlaterally by a distance substantially greater than the distance by whichthe parallel surfaces :6 are spaced apart. The surfaces 6 and '8 areconnected by surfaces 7 which are inclined upwardly and inwardly towardsone another. The surfaces 6 and 8 are parallel with the longitudinalmid-plane of the outer member 1. Towards the lower end of the channel 5,the surfaces 8 are continued as surfaces 9 which extend inwards at rightangles to the surfaces 8 and the surfaces 9 are connected by asemicircular surface 10. From the above description it will be seen thatthe boundary surfaces of the channel 5 are such as to provide the twoside walls 3 of the outer member 1 with two oppositely disposed recesses11 and that the surface 10 provides a groove 12 in the lower wall 4- ofthe outer member 1.

Referring to FIGURE 1, the outer surface 16 of the outer member 1 formsthe major portion of a cylinder. The inner member 2 has an exteriorsurface which is so shaped as to be complementary to the inner surfaceof the outer member 1. The inner member thus has two oppositely disposedparallel surfaces 60, two oppositely disposed parallel surfaces andinclined surfaces 70 connecting surfaces 60 and 80, and surfaces 90,surfaces 60, 70, 80 and of the inner member corresponding respectivelyto the surfaces 6, 7, 8 and 9 of the outer member -1. The inner memberis also provided with a groove of semicircular shape in cross-sectionand which is adapted to be brought into registration with the groove 12of the outer member 1. The inner member also has a through passage 13 ofcircular cross-section;

The inner member is so dimensioned as to be capable of making a slidingfit in the outer member the engagement of the two members being broughtabout by a relative axial movement of the members. When thus broughtinto engagement a through passage is provided by the cooperation of thegrooves 12 and 120 for the reception of a stranded conductor 14 and thethrough passage 13 provides for the reception of a stranded conductor15.

When the outer and inner members 1 and 2 are brought into engagement, itwill be seen that the cooperation of the surfaces 7 and 70 preventsrelative radial outward movement of the two members and that theco-operation of the surfaces 9 and 90 prevents relative radial inwardmovement of the two members. The two members when fitted together thusprovide for the obtaining of a through passage of predeterminedcross-sectional area and shape so that it can be ensured that theconnector fits uniformly around the circumference of the conductor 14housed in the through passage. This is of advantage in ensuring asatisfactory joint between the two conductors when applying acompressive force to the outer surface of the connector as a moreuniform interlocking between the conductor 14 and the outer and innermembers 1, 2 can be obtained. 'Furthermore, by providing for apredetermined cross-sectional area and shape of the passageaccommodating the conductor 14, the connector can be more readilydesigned to accommodate a given size of conductor than would be the caseif the members 1 and 2 did not define a passage of definite size andshape.

In use the connector will accommodate a continuous or uncut conductorand a second conductor which can terminate within or outside theconnector. Since one end of the conductor 15 has to be inserted into thepassage 13 or alternatively, the inner member 2 be threaded over thatconductor, it follows that the conductor M will be the uncut conductor.From FIGURE 1 it will be seen that after assembly of the inner member 1and outer member 2, the inner member has an exposed surface 17 whichforms part of a cylinder and forms a smooth continuation of thecylindrical surface 16. Although this is not essential since the surface17 could be disposed either within or outside the surface 16, theprovision of a surface of the inner memher 2 to complete the cylindricalperiphery of the outer member 1 has the advantage of facilitating theuse of a tool having compression jaws of a simple construction and italso facilitates the application of insulating material in tape formaround the connector after compression, should that be necessary ordesirable. It also facilitates the enclosing of the connector in acasing of more simple construction than would be the case if the innermember were to project radially beyond the periphery of the outermember 1. As indicated above, however, the inner member 2 .may bearranged to project radially outside the outer member and the passage 13for accommodating the conductor 15 may be disposed radially eitherwholly outside the cylindrical surface 16 or partly outside that surfaceand partly within. In the construction illustrated the passage 13 islocated wholly within the outer member 1.

From FIGURE 1 it will be seen that the two conductors 14 and 15 areseparated by an intervening portion 18 of .the inner member 2. Theconductor 15 preferably makes a fairly close sliding fit within thepassage 13.

In order to complete the joint between the conductors 14 and 15 afterassembly, a compressive force of an appropriate value is applied to theexterior surfaces 16 and 17 of the outer and inner members 1 and 2respectively. This compressive force may be elfected by the use of ahand or power operated tool, for example, a hydraulically operated tool,having jaws of an appropriate shape.

In FIGURES 4 and there is shown an outer member 1 which is of the samegeneral construction as that shown in FIGURES 1 and 2 but the side walls3, instead of hav- "ing cylindrical outer surfaces, have outer surfaceswhich are each provided mainly by flat surfaces 21 which are parallelwith one another and with the surfaces 6 and 8. At their lower ends thetwo surfaces are connected by a surface 22 forming part of a cylinderand providing the exterior surface of the lower wall 4 of the outermember.

At their upper ends the flat surfaces 21 are connected to the upper endsof the surfaces 6 by surfaces 23 forming parts of cylinders. Theinternal shape of the outer memher shown in FIGURE 4 and theconstruction of the inner member are as shown in FIGURE 1, althoughgreater .areas of contact between the outer and inner membersappropriately shaped jaws, the final shape in cross-section of thecompleted joint may be of circular or non-circular cross-section. Byapplying circular compression to an assembly consisting of an inner andan outer member assembled to enclose a pair of conductors in the mannershown in FIGURE 1, but with the outer member constructed as shown inFIGURE 4, the completed joint may be given a circular configuration incross-section, as shown in FIGURE 6. Alternatively, by applying ahexagonal compression to the circular configuration shown in FIG- U RE1, the final configuration of the completed joint may be as shown inFIGURE 7, from which it will be seen that the connector has been given ahexagonal shape in cross-section. Normally the shape of the connectorbefore compression and the shape of the tool used for making thecompression would be such as to result in a circular configuration aftercompression.

The effect of the compression is to deform the outer and inner membersand to form indentations in the surfaces of the conductors, theindentations being entered by the adjacent parts of the two members andto effect a deformation and compacting of the wires of the conductors.The forming of the indentations and the penetration of the adjacentparts of the connector is illustrated in FIGURE 8, the conductor 15being shown with a portion 19 of reduced diameter and the conductor 14being shown with a portion 20 of reduced diameter, the reductions havingbeen brought about by the subjection of a compressive force to theassembly. An interlocking engagement is thus provided between theconductors and the adjacent parts of the connector. The compression alsohas the elfect of forming those portions of the two conductors lyingwithin the connector into bodies which to a large extent are solidmasses of metal.

If it be assumed that the conductor 14 is a main conductor forming partof an overhead line distribution system and that the conductor 15 is aconductor to be used for tapping off current from the main conductor, ajoint between the two conductors can be made in the following manner.With the inner member 2 removed from the outer member 1, the latter isbrought into position relative to the conductor 14 such that the latteroccupies the groove in the outer member. This can be conveniently doneby inverting the outer member and placing it over the main conductor sothat the latter supports the outer member. The inner member can then beslid axially into the outer member with or without the tapping conduotorbeing already in position. The inner member is retained in positionwithin the outer member. If the branch conductor is not already inposition it can be threaded through its passage in the inner member sothat its end projects beyond the latter. It may be bent over at itsprojecting end to prevent it pulling back through the inner member. Thejoint can then be completed with the aid of a suitable form ofcompression tool.

By providing the outer and inner members with engaging surfaces whichprevent the two members falling apart when assembled, the linesman orjointer can have both hands free to operate the joint forming tool, thusfacilitating the making of the joint. By providing the outer and innermembers with engaging surfaces preventing relative radial inwardmovement of the two members,

a more uniform distribution of the compressive forces around thecircumferences of the two conductors is ob tained, overcompression ofthe main conductor and undercompression of the branch conductor and poorcompacting of the wires of the conductors, being avoided.

By housing the two conductors in separate passages a greater degree ofuniformity of compression and compacting of the wires of the conductorscan be more readily obtained and there is complete circumferentialcontact between each conductor and the adjacent parts of surface or coldweld contact between the members and the conductors. These featuresprovide for an improved electrical performance of the joint and are,therefore, beneficial whether the joint is used with overhead orunderground conductors. The joint is also sound mechanically.

As will be appreciated the engaging surfaces preventing radially outwardand inward movement of the inner and outer members after assembly neednot necessarily have the shapes shown in the drawings but may be made ofother shapes. The shapes shown, however, have the advantage ofsimplicity of construction of the connector. Furthermore, the connectormay be used for making a joint between conductors of non-circularcross-section and the passages provided for the reception of theconductors be shaped in cross-section to suit that of the conductors tobe housed in the passage.

The surfaces of the connector with which the conductors make contact maybe milled or otherwise roughened where necessary or desirable toincrease the electrical conductivity of the connector. If the conductorsare of different metals, for example, copper and aluminum, a liberalcoating of a corrosion inhibiting paste or compound may be applied tothat conductor made of a metal differing from that of the connector, thepaste or compound being also applied to the wall of the passage housingthat conductor. Alternatively the whole connector may be encased in ashroud or casing filled with an insulating compound.

What I claim as my invention is:

A two-part compression connector for making an electrical and amechanical connection between two conductors each composed of wiresstranded together, the said connector consisting of an outer part ofmalleable metal and an inner part of malleable metal, the outer parthaving two oppositely disposed spaced side walls and a third Wallconnecting the two side walls, the third wall having a longitudinallyextending groove and the three walls forming a recess in the outer partwhich is open on one side thereof, the inner part having alongitudinally extending groove therein and a longitudinally extendingpassage separated from the groove in the inner part by a portion of theinner part, the two parts being so dimensioned that upon assembly, theinner part lies substantially wholly within the outer part in acircumferential direction, the two parts having engageable surfaceswhich prevent engagement of the two parts otherwise than by a relativeparallel longitudinal movement of the two parts, the grooves in the twoparts, upon assembly of the parts, cooperating to form a single passagefor the reception of a conductor and each being of uniform area incross-section throughout its length and the engageable surfaces of thetwo parts preventing relative radially outward and radially inwardmovements of the two parts upon assembly of the parts.

References Cited in the file of this patent UNITED STATES PATENTS1,975,683 Ohilds Oct. 2, 1934 FOREIGN PATENTS 730,579 Great Britain May25, 1955

